1. Field of the Invention
The present invention relates to a SiC member useful for heat treating semiconductors and a method of fabricating the same.
2. Description of the Prior Art
Since silicon carbide excels in heat resistance, the frequency of its use is increasing for applications that include, for example, a susceptor, a wafer holder, a thermal uniformity plate, a thermal uniformity ring, and a dummy wafer. To obtain silicon carbide with purity levels equivalent to that of quartz glass to be used for such applications, generally a CVD-SiC film (CVD-SiC film silicon carbide film formed by the method of Chemical Vapor Deposition) is formed on the surface of an SiC substrate. Further, to increase the purity of the CVD-SiC film, a CVD-SiC film can be formed on a substrate such as carbon which substrate can then be removed by oxidation, leaving a single substance of CVD-SiC.
The CVD-SIC film has a very small impurity content, and exhibits a yellow color or a green color which is the color intrinsic to SiC. The semi-transparent nature of a thin CVD-SiC film is evidence of the high transmittance of light through the CVD-SIC film in the visible ray region or its neighboring frequency region.
In semiconductor manufacturing, particularly in the single wafer heat treatment process in which wafers are processed one by one, a rapid thermal process (RTP) is adopted. Such a process uses an infrared lamp as a heat source to improve the temperature throughput. However, to uniformly increase the wafer temperature rapidly, the heat treatment members used in this process must also be heated correspondingly. In other words, a favorable heat response characteristic is required of the heat treatment members.
Recently, a single CVD-SIC material was employed in the RTP as a means to obtain a high-purity and low-heat-capacity heat treatment member for semiconductors. An important consideration in this process is the infrared ray transmittance of the CVD-SiC material. If the CVD-SiC has a sufficiently high purity, it is able to transmit not only visible light but also light in the infrared region. Generally, CVD-SiC absorbs a small amount of infrared rays. For this reason, heat treatment members formed from CVD-SiC are more difficult to heat than the wafer. As a result, a temperature distribution occurs in the wafer, resulting in slip in the wafer.